林召强
,
马力
,
闫永贵
中国腐蚀与防护学报
在恒定阴极电位下利用慢应变速率拉伸试验研究高强度船体结构钢焊缝的电化学性能和力学性能。结果表明，试样拉伸断裂主要发生在焊缝的熔合区；结构钢的阴极极化程度对抗拉强度和屈服强度的影响不大；随阴极电位负移，船体结构钢在海水中的延伸率、断裂时间和断裂应变率逐渐减小, 并且当施加阴极电位为-0.89 V（vs SCE）时各项性能最佳。同时，随着阴极电位负移，断裂方式逐渐从韧性断裂向脆性断裂发展，氢脆敏感性逐渐增加，在 -0.70 V~-0.89 V（vs SCE）之间氢脆敏系数低于5%，不发生氢脆；当电位负于-0.94 V（vs SCE），氢脆敏感性迅速提高，当极化电位为-0.99 V （vs SCE）时氢脆系数显著增大至20%，断口开始出现解理单元细小准解理断裂特征；在负于-1.04 V（vs SCE）时，氢脆系数已高于25%，进入危险区，且断口开始出现较多解理单元粗大的准解理、解理等氢脆断裂特征；随着电位继续负移至-1.14 V（vs SCE），断口完全出现解理组织、沿晶、穿晶结构或者两者混合的氢脆断裂特征。。
关键词:
氢脆
,
cathodic polarization
,
slow strain rate test
,
welding line
,
cathodic potential
S.H. Dong
,
Y.M. Lu
金属学报(英文版)
Based on the theory of hydrogen enhanced localized plasticity of the hydrogen induced cracking and considered the effect of residual stress produced by eliminated stress heattreatment, a fractal model of hydrogen induced cracking was presented, and a relationship among the effective surface energy T( H), fractal dimension D and stress intensity factor of hydrogen induced cracking, KIH, for welding pipeline under hydrogen environment was set up, from which the relationship of D and KIsCC is obtained. The model was verified experimentally to be correct.
关键词:
hydrogen environment
,
null
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null
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null
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